title: A spliceosomal recycling factor that reanneals U4 and U6 small nuclear ribonucleoprotein particles.
abstract: The spliceosome removes introns from pre-messenger RNAs by a mechanism that entails extensive remodeling of RNA structure. The most conspicuous rearrangement involves disruption of 24 base pairs between U4 and U6 small nuclear RNAs (snRNAs). Here, the yeast RNA binding protein Prp24 is shown to reanneal these snRNAs. When Prp24 is absent, unpaired U4 and U6 small nuclear ribonucleoprotein particles (snRNPs) accumulate; with time, splicing becomes inhibited. Addition of purified Prp24 protein regenerates duplex U4/U6 snRNPs for new rounds of splicing. The reannealing reaction catalyzed by Prp24 proceeds more efficiently with snRNPs than with deproteinized snRNAs.
authors.affiliation: University of California, San Francisco, School of Medicine, Department of Biochemistry and Biophysics, San Francisco, CA 94143-0448, USA.
authors.forename: P L
authors.initials: PL
authors.lastname: Raghunathan
authors.forename: C
authors.initials: C
authors.lastname: Guthrie
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001482:Base Composition; D005656:Fungal Proteins / Q000378:metabolism*; D008957:Models, Genetic; D012326:RNA Splicing; D012331:RNA, Fungal / Q000378:metabolism; D012342:RNA, Small Nuclear / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D017414:Ribonucleoprotein, U4-U6 Small Nuclear / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D017381:Spliceosomes / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D012331:RNA, Fungal; D012342:RNA, Small Nuclear; D016601:RNA-Binding Proteins; D017414:Ribonucleoprotein, U4-U6 Small Nuclear; D000255:Adenosine Triphosphate